Agree with freelander there.
I haven't got them in the SV, but I've fitted Osram Silverstars in the Toyota to replace the original bulbs, interestingly they were bog standard Osram H4 bulbs, so it gives a direct comparison of the effectiveness of the Silverstar spec.
Yes, they give crisp and clean white light, and noticeably better illumination at say 50-100m range, they do what they claim. Also they say they have filters to make them OK with plastic lenses (the Toyota has plastic H/lamp lenses).
If you want "better" H/lamps, I recommend them, if you want "blue" on the other hand..............
http://www.powerbulbs.co.uk/
(no connection, just satisfied customer)